Assionob



Aug. 2, 1932. H. PlTMAN 1,869,

COMBINED TYPEWRITING AND COMPUTING MACHINE Filed Jan. 19, 1926 '2 Sheets-Sheet 1 Aug. 2, 1932. H. 1.. PITMAN COMBINED TYPEWRITING AND COMPUTING MACHINE Filed Jan. 19, 1926 2 Sheets-Sheet 2' Patented Aug. 2, 1932 PATENT orrlca HENRY L. PITMAN OF WES'IFIELD,

NEW JERSEY, ASSIGNOB, BY MESNE ASSIGNMENTS,

TO'ELLIOTT-FISHEB COMPANY, A CORPORATION OF DELAWARE COMBINED TYPEWBITING AND COMPUTING MACHINE Application filed January 19, 1928. Serial No. 82,228.

This invention relates to combined typewriting and computing machines of the wellknown Underwood-Hanson type, in which computing wheels are actuated by toothedracks formed upon pin-bars having digit index-pins. The lower ends of said indexpins are normally flush with the lower edges of the pin-bars. By means of interposed and related mechanisms said index-pins may, by operation of the numeral typewriter keys, be set so that their lower ends extend below the lower edges of the pin-bars. Each pinbar has nine index-pins corresponding to the significant numerals, and the spacin between the pins alo-ng the bar correspon s to the distance the rack must move to rotate a computing wheel from digit to digit.

A bar or general operator, transversely disposed relatively to and immediately below said pin-bars, is given a reciprocating movement after the index-pins have been set. In its forward movement, said bar, by means of the index-pins set in its path, moves the pin-bars forwardly, causing rotation of the computing wheels through a number of digit spaces corresponding to the index-pins which were set. The return movement of the general operator restores the rack-bars without reversing the computing wheels.

Said wheels during this return movement are actuated by the usual carry-over mechanism, which becomes active during .said return movement.

()ne of the features of this invention is the provision of improved means and a simple arrangement thereof, whereby the setting of any index-pin positively restores any other index-pin which has beenpreviously set in the samepin bar.

In said arrangement, the index-pins are square or rectangular in section, and are retained in vertical slots formed in a block fastened to the side of the pin-bar. Interposed between the block and pin-bar is a th n stamping of resilient material, having prongs withnodules formed on the ends thereof, said nodules serving as detents which co-act with suitable notches in the sides of the index-pin to hold said pins in either normal or depressed position. The

partitions formed between the vertical slots of the blocks in which the index-pins are retained, have notches which, with similar notches in the sides of the index-pins, form a depression or channel which is termina at each end by the outer sides of the slots in which the end pins are retained. Nested in said channel is a groulpl of blocks, each having an upprer surface s aped into an obtuse wedge. act with the upper ed es or shoulders of the notches in the sides 0 the indexins. The blocks are proportioned 'so that w enplaced end to end they occupy the length of the channel, in which they are nested to such an extent that only one pin can be fully depressed and entered betweenthe blocks. time a pin is depressed and entered between the blocks, some of the blocks are displaced along their channel. Conversely this displacement of said blocks causes the extrusion and positive restoration of a previously-depressed pin in the same bar.

One advantage gained by this invention is that it affords a' flexible index-setting device without the use of the springs and latch-bar usually employed in previous inventions. Examples of such previous inventions are shown in the atent to E. Thomas, No. 1,287,517, dated ecember 10, 1918, and the patent to H. Hanson, No. 1,291,859, dated anuar 21, 1919.

Anot er feature of the present invention is that by means of the positive displacement of the aforesaid blocks, any pin previously set is positively restoredby the setting of another pin in the same pin-bar. This feature is of particular advantage in combined typewriting and computin machines in which computations are ma e subtractivel as well as additively. Such a machine is i lustrated in the patent to O. Minton, No. 1,280,065, dated September 24, 1918, in which subtraction is effected by a complementary addition of the number to be subtracted. Said machine is set for subtraction by manually pressing a subtraction key, or the settin for subtraction may be automatically effected by the letter-feed carriage as it moves into a subtraction zone. When the machine is thus he sides of these wedges cohus, every .ly restored when the are provided for the purpose of set for subtraction, either manually or automatically, the digit 9 pin in each bar is set by means of suitable devices to be described later. In the present invention said devices include a bail actuated by the usual subtraction-setting devices, said bail acting directly upon each 9 pin to set it. Said bail is also extended to reach a 9 in in a pin-bar that has been advanced by t e denomination-selecting means. The pin for the digit 9 must be set in each bar, because it is a necessary condition in complementary subtraction that all the bars in which no number is indexed by operation of a numeral-key shall add 9. In each pin-bar wherein a si 'nificant number to be subtract-ed is indexed, the 9 pin is restored. By means of the present invention, this restoration is efi ected positively without the use of devices previously employed, such as a small lever mounted beside each 9 indezopin and means for actuating said levers to restore the 9 index-pin when another index-pin is set. In this invention saidsmall levers and actuating means are not necessary.

Another advantage gained by this invention is a reduced liability of errors in the computations effected by the machine. As

is well known a flexible pin-bar is useful in enabling the operative to easily correct an error made in Writing a number. Before the number is registered in the totalizer, the operative may correct the error by baclr-spacin the typewriter-carriage to the place where the wrong digit was printed, erasing said digit and writing the correct one in its place. By means of this invention the pin corresponding to the wrong digit is positivecorrect digit is printed, and its corresponding pin set. lhere is no liability of an error on account of a restoring spring being slug' ish or slight binding of the index-pin in its cage, because, in this invention, no restorin springs are used, and a slight binding of the index-pin in its cage would. not matter, as the pin i positively restored.

In machines of the type herein shown and illustrated, the pins are set by means of pinsetting bars, of which there is one for each digit. In the present invention 0 has a corresponding pin in each pin-bar. The 0 pins are not reached by the cross-bar on the general operator and are, therefore, inefiective to rotate the computing wheels. They restoring pins that were indexed through operation of the wrong numeral-keys. Other functions of said pins will be described further on. A 0 pin-setting bar is also provided. Said pin-setting bars are arranged over and be tween transverse rows of pins. A pin-bar in which a pin is to be set is pushed :forward by the usual denomination-selecting means actuated by the letter-feed carriage, so that the pins in said bar are directly below their respective pin-setting bars.

The pin-setting bars with their usual parallel motion linkages, rock-shafts, and subtraction-setting devices are built up into the usual frame-like structure. .This structure is substantially simplified in this invention, because it does not embody the elements formerly necessary for positively restoring the 9 pins in subtraction.

In this invention the 0 pin is used to restore any other pin after. the digit indexed by said other pin has been registered in the totalizer during a forward movement of the pin-bar. This restoration takes place when said pin-bar is almost at the end of its return movement. To this end there is provided on the pin-bar and adjacent to the 0 pin a small lever of the first order. One end of this lever engages the 0 pin by means of a notch in said 0 pin. The other end of the lever is engaged by a bail which eX- tends across and under all the pin-bars and 0 pindevcrs. By means of a suitable connection this bail-bar is actuated by the general operator when the pin-bars are almost fully restored, causing said bail-bar to rise, engage and actuate the 0 pin-levers, thereby causing all the 0 pins to be depressed and consequently causing all other pins that were set to be restored. The 0 pin is nor mally in a depressed position when no other pin in the bar is set.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure is a sectional side elevation of an Underwooddlanson combined typewriting and computing machine, showing only such parts as are necessary to illustrate this invention.

Figure 2 is a. perspective viev. of the pinbars and the means for restoring, after computation is effected, the pins that were set. This figure also shows means actuated by an elimination key for restoring pins that were set.

Figure 3 is a. detailed side view of some of the subtraction-setting elements.

Figure 4 is a cross section through one of the pin-bars, showing details of the index-pin and related arts.

Figure 5 IS a perspective view of indexcausin lgl 17. e platen is revolub y mounte Figure 10 is a side view of the index-pins and related parts, and shows one of the pins depressed.

Figure 11 is a diagrammatic view of the index-pins and inter-acting elements, and shows said pins in normal positions.

Figure 12 is a diagrammatic view of the index-pins and inter-acting elements, and shows one of said pins de ressed.

Alphabet keys 10 an numeral-keys 11 mounted upon the forward ends of levers 12 are operated to rock bell-cranks 13, which swing type-bars 14 upwardly and rearwardly type 16 to print a ainst the laten in a carriage 18, which is propelled by a springbarrel (not shown) and controlled in the usual manner by escapement-wheel 19 and dogs 20, the latter being operated b a universal-bar 21, which is actuated by -heels 22 on the type-bars. Connection between the escapement-mechanism and typewriter-carriage is effected by means of a rack 23 swung upon arms 24 from the typewriter-carriage. Said rack meshes with a pinion 25 connected to the escapement-wheel. Computing wheels 26 have a forward drivin ratchet connection (not shown) to pinions 2 which mesh with racks 28 formed upon pin-bars 29, there being one pin-bar for each computing wheel. Each bar carries a set of index-pins 30 which are depressible by means of linkages 31, the latter including pin-setting bars 32 and rockshafts 33 which have the usual arms 34 engageable by stems 35 pendent fromthe numeral-keys 11. Depression of any numeralkey 11 to operate its type-bar causes the depression of a corresponding pin-settin bar 32, whereby one ofthe index-pins 30 is depressed in the ath of a bar 36 on a eneral operator 37, w ich may be 0 erate by a crank 38 after all the desired index-pins 30 have been set. The crank is fixed upon a rockshaft 39, which carries a segmental gear 40 on each end, meshin with an idle pinion 41, the latter meshing with a rack 42 on each side of the machine. Said racks form part of the general operator 37.

In order to depress one of the index-pins 30, the pin-bar in which it is mounted must be pushed forward so that said index-pins come under the pin-setting bars 32. This is done by means of the usual denominationselecting mechanism which is controlled by the letter-feeding movements of the typewriter-carriage through a computing zone. Said mechanism includes a dog 45 mounted on the typewriter-carriage, and which, dur-.

ing letter-feeding movements of the carriage is effective to actuate denomination-selecting j acks 46, one after the other. Said denomi nation-selecting jacks when thus actuated depress thrust rods 47 whose lower ends are pivoted to levers 48, which operate linkages 49 to push the pin-bars forward by means of bell-cranks 50. Said linkages form a transposition device, whereby the order in which the pin-bars are selected is reversed from the order of operation of the jacks.

Thus,'by means of this transposition device,

the extreme right-hand jack 46 causes. the extreme left-hand pin-bar 29 to be selected, the other jacks and pin-bars being operated in following order. The usual Underwood denominational tabulating means are provided and include a set of denominational tabulating keys 53, which operate by the usual means (not shown) plungers 54, causing said plungers to rise in the path of counter-stops suitably mounted on the typewriter-carriage, When any ofthe tabulating keys are operated the rack 23, by means of connections (not shown), is disengaged from the escapement-pinion 25, and the car riage moves forward under the influence of its propelling spring until the counter-stop 55 strikes the plunger 54 which is raised in its ath.

he indexepins are arranged upon the pinbar 29 in a pin-block 58 having slots 59 formed therein, in which said index-pins may slide up and down. The lower ends of these pins are substantially flush with the bottom surface of said pin-block when said pins are in their upper or normal position. In each pin-bar there are nine index-pins, one for each digit, from 1 to 9, inclusive, and a. 0 pin 60. As will be shown, said 0 pin is normally down when no other pin in the bar is set. Each pin has formed in the side thereof a slot 61. A longitudinal cut in the side of the ineblock 58 forms therein the slots 62. Said slots 62 in the pin-block and slots 61 in the index-pins form a channel 63,'within which are placed, end to end, hardened steel blocks 64, each having up er surfaces 65 formed into an obtuse we ge, the sides of which are equally inclined toward the horizontal; Said blocks may have holes 64 to make them lighter and are proportioned, so that, when placed end to end, they occupy the channel to an extent that will leave a gap 66, see Figures 11 and 12. The blocks 64 have a slidin fit in the slots 62, are partially supported y the pins, and may be displaced so that the gap 66 may be 0 ened between any two blocks or between either of the end blocks and adjacent channel terminating wall 67 formed by the outer side of each end in-slot. Thus, wherever a pin is depressed t is gap' is opened under the pin and closed by the pin as the pin displaces its adjacent block. The displacement is effected by the camm'ing action of the shoulder 69 upon the adjacent wedge surface of the adjacent block, to spread the blocks a preplaces a. block, said block may, by displacement of the block in the opposite direction,

and the consequent restoration of the pin,

are effected when another pin is depressed,

and pushes said block aside either by acting on it directly, if the two pins are adja-.

cent, or by means of intermediate blocks, if the pins are not adjacent. The latter condition is illustrated in Figure 12, where the depression of the 5 pin, for example, has

caused the restoration of the pin by dis-- placing the blocks, intermediate of said pin and 0 pin, toward the left. If, for example, the 4 pin is then depressed, it would cause the restoration of the 5 in by displacing the block, between said 4 pin and 5 pin, toward the right. The gap 66 is proportioned so that only one pin at a time can be fully depressed.

The index-pins are detented in either upper or lower position by means of a simple device consisting of a thin stamping 72, of resilient material, having prongs 73 formed thereon. Said prongs are given an initial set so that nodules 74 formed on the ends thereof are pressed against and detent the index-pins it in either upper or lower position by means of slots and 76 formed in the sides of said index-pins, see Figure 4. The stamping 72 is placed between the pin-block 58 and pin-bar 29. Tongues 77, formed between the prongs 73, cover the slots 59 in the pin-block and retain the blocks 64. The ends of said tongues bear upon the partitions formed between the pin-slots 59, The upper web 78 of the. stamping retains the upper part of the index-pins and theup er ti s of the blocks 64. The assembly of t e in exing elements is secured by means of screws 79, threaded into the pinblockafter passing through holes80 in the pin-bar 29 and the stamping 7 2. The pin-bar 29 is suitably recessed at 81, see Figure 4, to provide clearance for the prongs 73 when they bend outward as an index-pin is actuated.

The feature of positively restoring one index-pin when another one is depressed makes it possible to simplify some of the elements necessary for subtractive computation. The usual means for subtraction include the sub traction-setting key 82, connected by a link 83 to an arm 84 keyed to a shaft 8."). Said shaft has also keyed to it a latch 86, see Figure 3, which holds in normal forward position a subtraction bar 87 against the tension of a sprin 88. In Figure 3, the subtraction key (not s own) has been pressed in, causing the latch 86 to be withdrawn from the subtraction bar 87, which, thus released, is pulled rearwardly by the spring 88. The latch 86 may'also be withdrawn by the usual means (not shown) which are automatically operated by the movement of the letter-feed carriage into a subtraction zone. The rearward movement of this subtraction bar causes a bail 89, extending across all the pin-bars, to set each 9 pin in said pin-bars. Said bail has an extended ledge 89 to reach the 9 pin in a bar that may have been advanced by the denomination-selecting means. Said bail is operated by the usual means including a 7 blank 91 fastened to a bail-shaft 92 to which the bail is keyed. Said bail-shaft may be pivotally supported upon the pin-setting frame 93. The blank 91, as the subtraction bar moves rearwardly, is engaged by a springpressed hook-shaped member 94 pivoted to the subtraction bar, causing the bail-shaft to rotate. Said bail is thereby depressed and sets the 9 index-pins 30 as the subtraction bar moves rearwardly. Toward the end of the rearward subtraction bar movement, said hook-shaped member is withdrawn from the blank when an extension 95 thereon is arrested by the abutment 96. The withdrawal is effected by thus causing the hook-shaped member to slightly rotate about its pivot 97. A spring (not shown) then retracts the bail. The cross-bar 36 restores the subtraction bar by means of a shoulder 87, on said subtraction bar, and a spring 98 forces the latch 86 into the notch 98*.

Heretofore, a small lever of the first order was pivoted on the side of each pin-bar, and one end thereof engaged the 9 pin. The other end of said lever was raised when the 9. pin was set through pressing the subtraction key. By means of a bar similar to bars 32 and having corresponding linkage, which was connected during subtraction to each rock-shaft 33, except the ninth, said other end of the lever was depressed when adigit to be subtracted was indexed. In this manner the 9 pin was positively restored. Because the 9 pins are positively restored by means of the blocks 64, such means are not necessary in this invention, and the elimination thereof results in a simplified pin-setting frame arrangement which also includes elements for indexing a 0 pin. A plan view of said arrangement is shown in Figure 6. As the machine is set for subtraction all the rock-shafts are shifted by sliding them forwardl by the usual means which include a swinga le transverse-bar 99 pivoted at 100 and engaging the rock-shafts 33, by means of slots 101 therein. Said bar is connected to the subtraction bar by means of the usual connection including a bell-crank-lever 102. As the have been omitted for the sake of clearness, pins. Said sprin as shown in Figure 2, is but which are effective during subtraction. applied at one en of the shaft 106 to rotate The numbers indexed in the pin-bars are said shaft in a counter-clockwise direction. additively or subtractively registered in the Said rotation is limited by a pin 126 driven 5 computing wheels 26, b givm the general into the left side frame of the computing sec 70 operator 37, which inc udes t e transverse tion, said pin stoppin the lever 111 with bar 36, a single reciprocating forward and which the arm 110 in he shaft co-acts.

rearward movement. Said bar in its for- Variations may be resorted to within the ward movement encounters the lower ends of scope of the invention, and portions of the the index-pins projecting below the pin-bars, im rovements ma be used without others. 7 5

thereby causing said pin-bars to move foraving thus escribed my invention, I ward and rotate the computing wheels. In claim: I g its return or rearward movement, said trans- 1. In a computing machine having a deverse bar engages shoulders 103, formed on nominational series of bars, pins settable in the pin-bars and returns said pin-bars withsaid bars, pin-setting members adjacent said 80 out reversing the computing wheels in the bars for setting said pins, and numeral-keys well-known manner shown and described in for operating said members; means co-acting the patent to H. Hanson, dated September 24, with said ins in each pin-bar and including a 1918, No. 1,279,688. I cam-face movable element between each two During this return movement, 'the usual adjacent pins in said bar, whereby the depres- 85 carry-over-mechanism 104, which has a onesion' of a pin displaces one or more of said eleway drive through the pinion 105 becomes ments and thereby causes the extrusion and effective; During said return movement, the positive restoration of a previously-set pin index-pins are re-set. To accomplish the rein the same bar.

setting of the index-pins, there is provided a 2. In a computing machine'having numer- 90 cross-shaft 106. pivoted in the side frames 107' al-keys rangin from 0 to 9, pin-setting of the computing section. Said shaft has members opera le by said keys, and bars arkeyed thereon a bail 108 having a broad upranged in denominational series and each per surface 109. By means of an arm 110 having a pin settable by one of said memkeyed to said shaft, and a lever 111 having a bers: means including se arate movable ele- 95 pin 112 in one end thereof, said lever being ments co-acting with sai pins, whereby the pivoted upon the left-hand side frame of'the depression of a pindisplaces one or more computin section, said shaft may be slightly of said elements and thereby causes the exrotated c ockwise. This occurs during the trusion and positive restoration of any other return movement of the general operator, pin previously set in the same bar. 100 when the usual spring-pulled one-way cam- 3. In a computing machine, the combinapawl 113, pivoted on the general operator, ention with an indexing pin-bar having settable counters and engages the edge 114 formed at ins slidable in transverse channels in said the end of said lever, causing said lever to roar, of a longitudinal channel intersecting tate until the tip 115 thereof may escape from said transverse channels and formed by slot- 1 5 said cam-pawl, as shown in Figure 8. The ting said pins and the partitions formed berotation of the shaft 106 causes the bail surtween said transversechannels, and movable face 109 to be raised and presented against elements assembled within said longitudinal rounded ends 117 of levers 118 ivoted on channel and so proportioned that when each pin-bar at 119. Each of said levers is placed end to end they occupy all of said rotated" thereby, and the 0 pin 60, with longitudinal channel less a predetermined which each lever is articulated by means of a working gap, said movable elements being I slot 120 in the side of said pin, 18 depressed. operative by the full depression of one of By the depression ofthe 0 pins in this said pins to displace said elements by filling 5o manner, just before the pin-bars are returned, the gap, and operable by the depression of all the index-pins which were set and rea second pin to cause the extrusion and posistored, and a new number may be indexed in tive restoration of the first pin. the in-bars. .By means of a flange 121 on 4. The combination of numeral-keys,rows its pivot stud,seeFi re 5, each of said levers of index-pins settable by said keys, and a' 55- 118 is spaced from its pin-bar so as to clear confined row ,of movable elements foreach the stamping 72. A clearance 127 is also row effective to prevent simultaneous setting formed on the pin-block 58 for said'lever. of two index-pins in any row, each element All the index-pins may be restored in case having beveled shoulders to enable it to be of error by pressing an elimination key 122. cammed in opposite directions by the adja- 1 a0 Said elimination key, connected by a link 123 cent index-pins, for restoring the prevlous yto an arm 124 fastened to the shaft 106, may set index-pin. cause said shaft to rotate and restore the pins 5. The combination of numeral-keys, rows in the manner just described. of index-pins settable by said keys, and con- A torsion spring 125 is provided to restore fined rows of movable elements effective to -6 the bail after said bail has restored tli e 0 prevent simultaneous setting of two indexwhich said elements may slide,

' able pin-bar and &

pins in any row, each element having heveled shoulders to enable it to be cammed in opposite directions by the index-pins, for restoring the previously-set adjacent pin, and means in WlllCll the pins and elements are mounted, said mounting means having rows of vertical guiding slots for said pins, said guiding slots supporting the index-pins for the camming actions upon said elements, and said mounting means formed with supporting means upon which the movable elements rest while being cammed. 4

6. An indexing mechanism for computing machines, including rows of index-pins, each row including nine digit-pins, keys for setting said pins, means for detaining any set pin, and means for enabling the power of i any of said keys to be utilized to force back to normal posit1on any pre-set pin.

7. In a computin machine having dials and a set of bars, eac provided with settable index-pins for driving the dials, and a general operator to engage said pins; means oper ative to restore a wrongly-set pin by the subsequent setting of a correct pm, said restoring means including a train of separable elements slidably displaceable upon said pinbar, said bar having a grooved portion along said elements movable in said groove by means of the indexpins, and eifectlve to prevent simultaneous depression of two pins, and to restore any previously set pin.

8. In a computing machine, the combination of a computing bar having a series of index-pins key-settable therein, and a train of separable elements assembled end to end within a groove out along said bar and cut crosswise through said index-pins, the setting of any index-pin displacing one or more of said elements along the groove to block the simultaneous setting of another index- 9. In a computing machine having a mova series of he -settable indexing pins, the combination 0 means operative to eliminate an incorrectly-set pin by the subsequent setting of a correct pin, said means including a groove in said pin-bar, and a series of separable wedge-shaped elements slidably displaceable along said oove in the pin-bar .to block the depresslon of all the pins by their endwise dlsplacement by one pin, said wed e-shaped elements being operative to forci ly restore a depressed pin when a second pin is depressed,

10. In a computing machine, the combination with a com utmg bar havin a series of key-settable 'mdexlng pins, 0 self-correcting means effective to restore a misset indexed pin by a subsequent key-set pin, said meansincluding a groove formed longitudinally of said bar and across each indexing pin, and a separable cam for each indexing pin assembled as a series within said one index-pin will forcibly aeeasee groove, each cam displaceable by any indexing pin and each cam en'gageable with an indexed pin to restore said indexed pin throu h the redisplacement of the series of cams by any pin subsequently set by a key.

11. In a computing machine, a computing bar having key-settable pins therein, and having a continous longitudinal groove, said groove continuing through each settable pin, and a train of separable elements assembled end to end within said composite groove, one element for each pin, said train of elements being displaceable by the indexing of any pin to prevent ,the simultaneous setting of two pins in the bar, and to restore a pin previously set by mistake.

12. In a'computing machine having a bar and a series of key-depressible indexing pins, the combination of a continuous groove through both pin-bar and pins, a train of separable elements mounted within said groove, and movable as a series by the depression of a pin and operable through their form and location to prevent the depression of a second pin without restoring the first pin depressed.

In a computing machine, a self-correcting indexing mechanism including a computing bar having a groove longitudinally thereof, a series of. key-set index-pins settable crosswise of. said bar, each index-pin havin a groove alignable with said groove in said bar, and a series of separable elements, one element for each index-pin, said elements assembled as a connectible series within the groove formed in said bar and index-pins, each element so formed that the displacement thereof within said groove by the setting of re-displace said series of elements and eflect the restoration of the first key-set index-pin.

14. In a computing machine, the combination of a bar movable to compute and a unit of key-settable index-pins secured to the side of said bar and operative to predetermine the extent of movement for said' bar in computing, said unit including a detached housing having a series of transverse open grooves, the indexins being slidable within said grooves an flush with the face of said housing, a groove being cut longitudinally of said housing and transversely through said index-pins, and a series of separable elements arranged within said longitudinal groove and each element havin a formation eflecti've to displace the other e ements and limit the setting of the index-pins by the keys.

In a computing machine having computing devices including a denominational barhaving a series of key-set indexing pins, the combination of a series of pin-restoring elements on the pin-bar including a groove along said pin-bar and across all of said pins, separable blocks, one block for each pin and the series of blocks movable along said groove, each block formed with cam-facesin said pin-bar and operable to limit 7 the'extent of longitudinal displacement for said blocks as a series 'in two directions to limit the full depression of one pin and prevent the depression of any other pin without simultaneously restoring the first pin depressed.

16. In a computing machine, having a pinbar and a series of key-depressible indexing pins, the combination of a groove through 0th bar and its pins, a train of separable elements mounted within said groove to slide as a series through the groove in the series of index-pins by the depression of a pin, and end stops formed in the bar to limit the sliding movement of the separable elements, said elements as a train having an endwise lost motion of predetermined extent between said stops and an endwise abutment as a series to provide a working gap between sections of said elements whereby any pin when depressed closes up the gap, and wedges between the divided train, said wedgeddn pin preventing the simultaneous depression of another pin.

17. In a computing machine, a row of settable index-pins and, means to enable any' pin to restore any previously set pin, including a row of co-operative pin-restoring elements having a longitudinal movement and having wedging sections engageable by said row of index-pins, each index-pin insertible between the wedge-sections to effect endwise displacement of said pin-restoring elements, and said wedge-sections being eflective upon the other index-pins to restore any index-pin set by mistake.

, HENRY L. PITMAN. 

